My first BIG SBG game was at a GW and I took all of my models (a baker's dozen of WoMT, half a dozen Warriors of Rohan, a WoMT Banner Bearer and a WoMT Captain with shield) and was lending a few to my friend (from that lot) and we were given a whole flank to deal with, on our own, against 30 Warg Riders (including Sharku and Gothmog on Warg), whereas the other flank got over 50 KoMT, 30+ Rohirrim and the Fellowship, as well as hordes of infantry, against: a few dozens goblins, a few orcs and a smattering of Uruk-hai.
Anyway, behind the gates (Evil were defending) were about 6 Trolls, Sauron, a Balrog and a Mumak. Gates opened on turn 1, Sauron came out surrounded by trolls, Aragorn moved forwards, then used a Heroic Move (or something) to get closer. Next turn, he got Compelled (or Transfixed or whichever spell I mean, lol) and was moved straight into combat and smashed to smithereens. Gandalf was killed (by shooting or magic or something) and, because the odds were ridiculous against Good, the GW staffers allowed us to replace him with Gandalf the White, but he had to wait a turn and enter from the back of the board. The Mumak was killed in that time and (for no logical reason), said it came on there too. It promptly flattened him and legged it up behind the troops on the right flank (with all of our cavalry) and ran riot.
Meanwhile, on my flank, we had 6 archers, 2 throwing weapons, 2 Rohan w/shields and my mini-shield wall (captain and banner, backed up by 4 WoMT w/shields and 5 w/spears and shields) and managed to hold the line with no casualties for 6 turns before we had to leave!